Flush valve

1 . A flush valve comprising:

a valve housing defining a fluid passageway between a fluid inlet and a fluid outlet, the fluid passageway having a diaphragm valve seat disposed between the fluid inlet and the fluid outlet;

a diaphragm assembly including a diaphragm and a disc, wherein the disk defines a central axis and an aperture extending axially therethrough, the diaphragm having a primary opening that receives the disc therein, wherein the diaphragm assembly is disposed in the fluid passageway and is movable axially between an opened position in which the disc of the diaphragm assembly is not in contact with the diaphragm valve seat and a closed position in which the disc of the diaphragm assembly is in contact with the diaphragm valve seat;

a chamber in the fluid passageway established by a presence of the diaphragm assembly in the fluid passageway; and

a relief valve configured to selectively control fluid flow from the chamber to the fluid outlet, the relief valve comprising a relief valve housing, a stationary valve element at least partially positioned within the relief valve housing, and a rotatable valve element at least partially positioned within the relief valve housing, wherein each of the stationary valve element and the rotatable valve element have at least one opening and are rotationally positionable relative to one another to regulate fluid flow, wherein the relief valve housing is at least partially positioned within and movable axially along the aperture of the disk while forming a water-tight seal therebetween, and wherein the relief valve housing defines a valve inlet open to and in fluid communication with the chamber and a valve outlet in fluid communication with the fluid outlet.

2 . The flush valve of claim 1 , wherein when the diaphragm assembly is in the open position and the relief valve is in the closed position, fluid pressure builds in the chamber causing the disc to contact the diaphragm valve seat thereby forming a seal therebetween, returning the diaphragm assembly to the closed position.

3 . The flush valve of claim 1 , wherein the chamber in the fluid passageway is established by a presence of the diaphragm assembly in the fluid passageway and a fixed member disposed within the valve housing, the fixed member contacts the diaphragm in at least one radial position and has an extension that extends away from the diaphragm assembly, the extension of the fixed member has an inner chamber.

4 . The flush valve of claim 3 , wherein the inner chamber of the fixed member is configured to receive a motor and a gear train and is coaxial with the relief valve.

5 . The flush valve of claim 4 , wherein the relief valve is configured to be coaxial with the motor.

6 . The flush valve of claim 1 , wherein the position of the rotatable valve element is configured to be controlled by a motor and a gear train.

7 . The flush valve of claim 1 , wherein the relief valve housing has an inlet region and an outlet region, the inlet region being configured to receive the stationary valve element and the rotatable valve element, the inlet region has two flat outer faces with one or more openings in selective fluid communication with the chamber, the outlet region being configured to allow fluid to pass through the valve outlet when the relief valve is in the open position.

8 . The flush valve of claim 1 , wherein the diaphragm valve seat defines a peripheral fluid passageway wherein the peripheral fluid passageway is in fluid communication with the fluid inlet and the fluid outlet when the diaphragm assembly is in the open position thereby allowing additional fluid to flow from the fluid inlet to the fluid outlet.

9 . The flush valve of claim 1 , wherein the diaphragm is configured to bend to allow the diaphragm assembly to move from the closed position to the open position.

10 . The flush valve of claim 1 , wherein the relief valve further comprises at least one seal that prevents fluid communication external to the fluid passageway.

11 . A flush valve comprising:

a valve housing defining a fluid passageway between a fluid inlet and a fluid outlet, the fluid passageway including a bypass opening allowing water under pressure supplied to the fluid inlet to pass into a chamber in the fluid passageway;

a relief valve configured to selectively control fluid flow from the chamber to the fluid outlet, the relief valve comprising a stationary valve element and a rotatable valve element each having at least one opening and being rotationally positionable relative to one another to regulate fluid flow; and

a manual actuation assembly configured to selectively open the relief valve in the absence of power to permit a flow of water from the chamber into the fluid outlet thereby relieving a fluid pressure in the chamber.

12 . The flush valve of claim 11 , further comprising a diaphragm assembly, wherein the manual actuation assembly is configured to permit a flow of water from the chamber into the fluid outlet such that the diaphragm assembly moves from a closed position to an opened position to permit water to pass from the fluid inlet to the fluid outlet.

13 . The flush valve of claim 12 , wherein, when the flush valve is activated, the relief valve is opened to permit the flow of water from the chamber into the fluid outlet thereby relieving the fluid pressure in the chamber and causing the diaphragm assembly to move from the closed position to the opened position.

14 . The flush valve of claim 12 , wherein when the diaphragm assembly is in the open position and the relief valve is in the closed position, fluid pressure builds in the chamber causing a disc of the diaphragm assembly to contact a diaphragm valve seat of the diaphragm assembly, thereby forming a seal therebetween, returning the diaphragm assembly to the closed position.

15 . The flush valve of claim 12 , wherein the chamber in the fluid passageway is established by a presence of the diaphragm assembly in the fluid passageway and a fixed member disposed within the valve housing, wherein the fixed member is configured to contact the diaphragm in at least one radial position and have an extension that extends away from the diaphragm assembly, and wherein the extension of the fixed member has an inner chamber.

16 . The flush valve of claim 15 , wherein the inner chamber of the fixed member is configured to receive a motor and a gear train and is coaxial with the relief valve, and wherein the relief valve is configured to be coaxial with the motor.

17 . The flush valve of claim 11 , wherein the diaphragm is configured to bend to allow the diaphragm assembly to move from the closed position to the open position.

18 . The flush valve of claim 11 , wherein the position of the rotatable valve element is configured to be controlled by a motor and a gear train.

19 . The flush valve of claim 11 , wherein the relief valve has a rigid frame, the rigid frame of the relief valve has an inlet region and an outlet region, the inlet region of the rigid frame being configured to receive the stationary valve element and the rotatable valve element, wherein the inlet region of the rigid frame has two flat outer faces with one or more openings in selective fluid communication with the chamber, and wherein the outlet region of the rigid frame is configured to allow fluid to pass through the relief valve when the relief valve is in the open position.

20 . The flush valve of claim 11 , wherein the relief valve further comprises at least one seal that prevents fluid communication external to the fluid passageway.